Tufts scientists got tadpoles to grow eyes on their back by manipulating membrane voltage gradients.
Using genetic manipulation of membrane voltage in Xenopus (frog) embryos, biologists at Tufts University's School of Arts and Sciences were able to cause tadpoles to grow eyes outside of the head area.
They changed the voltage gradient of cells in the tadpoles' back and tail to match that of normal eye cells. The eye-specific gradient drove the cells in the back and tail, which would normally develop into other organs, to develop into eyes.
According to Michael Levin, Ph.D., professor of biology and director of the Center for Regenerative and Developmental Biology at Tufts University's School of Arts and Sciences these findings identify an entirely new control mechanism that can be capitalized upon to induce the formation of complex organs for transplantation or regenerative medicine applications.
For every structure in the body there seems to be a specific membrane voltage range that drives organogenesis. By using a specific membrane voltage, the researchers were able to generate normal eyes in regions that were never thought to be able to form eyes. This suggests that cells from anywhere in the body can be driven to form an eye.